A minor one that also counts as a Funny moment: Malfoy, in a rare display of Slytherin cunningness, manages to talk Harry (and also himself) out of a confrontation with Zacharias Smith by pretending to agree to accept his challenge to a Wizarding Duel, then setting Filch on his tracks. This ends with both Smith and Ernie MacMillan getting a detention (plus a humiliating scandal), and Smith's attempts to explain himself only makes him sound more ridiculous (because why would someone like Malfoy ever agree to become Harry's second)?
Pansy Parkinson taking out the troll by reducing its head to mush. Apparently, it was so cool, that Ron (who can’t stand Slytherins) does the same thing later to the troll beneath the 3rd floor corridor.
